Carrageenan and gut inflammation in bowel disease
What it found
In animals, degraded carrageenan caused gut ulcers and inflammation, and in a small human trial, carrageenan capsules were linked to more ulcerative colitis relapses.
The authors say more research is needed before advising people with IBD to avoid it.
What they found
Studies in people
Colitis relapse in people
In a small randomized trial, three patients taking carrageenan capsules had a relapse of ulcerative colitis, compared with one in the placebo group. The doses used were lower than those in a typical Western diet.
Animal and lab studies
Gut ulcers in animals
In animal studies, degraded carrageenan triggered intestinal ulceration and inflammation. The severity increased with longer exposure.
Gut bacteria changes
Carrageenan can affect gut bacteria and reduce bacterial diversity. Some studies found a decrease in anti-inflammatory Akkermansia muciniphila and an increase in harmful bacteria.
Leaky gut
Carrageenan may increase intestinal permeability, contributing to 'leaky gut' syndrome. This was seen in animal and cell studies.
Blood sugar and insulin
Carrageenan may increase glucose intolerance and insulin resistance, according to animal studies.
Studies in people and animals
Cancer effects unclear
Some studies suggest carrageenan may inhibit cancer cell growth, but other animal studies found it increased colon tumors. The anti-cancer effect is still unclear.
What the authors conclude
“Further research is needed to determine whether carrageenan should be excluded from the diet of individuals with IBD.”
Also in their conclusions
- They conclude that additional randomized clinical trials are needed to answer whether carrageenan should be excluded from the diet of individuals with IBD.
- They advise that special attention should be paid to the exact nomenclature of carrageenan, distinguishing between carrageenan in food, degraded carrageenan, and poligeenan.
- They state that research should focus on examining both the effects of degraded carrageenan and carrageenan that is approved for human consumption.
How it was done
The authors wanted to understand whether carrageenan, a common food additive in the Western diet, affects gut bacteria, gut permeability, and inflammation, which could matter for inflammatory bowel disease.
They reviewed recent studies on carrageenan and its effects on gut bacteria, gut permeability, and inflammation. They searched MEDLINE and SCOPUS databases using terms like carrageenan, inflammatory bowel disease, cancer, food additives and gut bacteria, and food additives and autoimmune diseases.
What it can’t tell you
- Most studies on carrageenan and gut health were done in animals or cells, so they cannot show what happens in people.
- The human trial was very small, so its results may not apply to everyone with IBD.
- This review cannot prove that carrageenan causes IBD or cancer in people.
Who paid
- Conflicts
- The authors declare no conflicts of interest in this topic.
- Authors work at
- Medical University of Gdansk, Poland; Poznan University of Medical Sciences, Poland; Nicolaus Copernicus Hospital, Poland
The paper
- Title
- Carrageenan in the Diet: Friend or Foe for Inflammatory Bowel Disease?
- Type
- ReviewThe authors read earlier studies and describe what they found. It isn’t a new study.
- Evidence
- Studies in people · animals · lab
- Summarised from
- Full text
- Cite
- Kimilu N, Gładyś-Cieszyńska K, Pieszko M, Mańkowska-Wierzbicka D, Folwarski M (2024). Carrageenan in the Diet: Friend or Foe for Inflammatory Bowel Disease?. Nutrients. doi:10.3390/nu16111780Free full textPubMed 38892712DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error